(Inside Science) -- When a great musician like Hélène Grimaud sits in front of a piano and begins a Mozart concerto, something remarkable is happening in her brain. She will go into something like a trance -- you can see it in her face -- and Mozart goes on autopilot.

What is happening is called muscle memory or a flow state, said Alan Hugh David Watson, a reader in bioscience at Cardiff University in Wales, a musician himself. She can do that because of practice -- constant, singled-minded, seemingly endless repetition that only the most dedicated consider.

The best musicians begin playing -- and practicing -- before they are eight, Watson said.

The result may be a brain physically different from a non-musician's.

The simplest example of muscle learning may be what happens when you buy a new car, explained Watson. You don’t know where all the switches and dials are when you first drive it and have to take your eyes off the road to do anything with the dashboard. But after a while you can turn the heat up or change radio stations without looking. Your brain is wired for the instrument panel. In fact, most people probably drive in a flow state, their minds on something else.

So too is a musician’s brain while playing a sonata or a jazz riff.

A more extreme example may be baseball. A major league batter has to hit a ball buzzing at him at almost 100 mph, thrown from a distance of sixty feet, six inches, and he has less than a fourth of a second to respond. He must rely on muscle memory. If he thinks, he misses. A great hitter like the late Ted Williams still gets out two-thirds of the time.

Everyone who relies on muscle memory has one thing in common: practice. And the constant practice may physically alter the brain.

Gottfried Schlaug, of Beth Israel Deaconness Hospital in Boston and Harvard University in Cambridge, Massachusetts, found that the brains of musicians have more gray matter in one area of the brain than do people who are not professional musicians. The question is whether the people with the different brains were born that way or acquired the attribute by practice.

The scientific consensus seems to prefer the latter, although genetics and environment certainly play a part.

The brains of creative musicians are more efficient than the brains of most other people in some ways, according to Ana Pinho, a researcher at the Karolinska Institutet in Stockholm. She did a study of 39 jazz improvisational musicians by monitoring them while they played within a functional MRI-brain scan device.

She had the musicians lie down in the claustrophobic scanner tube and improvise music with one hand on a custom-made keyboard without moving their heads. She found there was less activity in parts of the brains of accomplished musicians, a relationship between brain efficiency and creativity, probably because of practice.

There also was more connectivity within sections of the brain in the more experienced pianists, she explained.

Other researchers found similar attributes. Scientists at the University of Montreal in Quebec took a group of musicians and non-musicians and attached a vibrating device to their fingers. Then the scientists, led by Julie Roi and Francois Champoux, played tones the subjects could hear and simultaneously feel through a single vibration on the finger.

When they heard a single sound, all reported the one vibration. But, when the single vibration came with two or more tones, the non-musicians said they felt multiple vibrations; the musicians insisted there was only one. Their brains -- wired by 15-25 years of practice -- did not allow interference with what they felt. They presented their paper at a neuroscience meeting last year.

The action takes place in the prefrontal cortex, particularly the lateral prefrontal cortex (involved in planning), the pre-supplementary motor area (involved in rhythm) and the dorsal premotor cortex (which understands melody). Separately, Schlaug also found that part of the increase is in part of the brain associated with finger movements.

Scientists have also found a relationship between music and reading. Experiments at Northwestern University in Evanston, Illinois showed that reading and music have common neural and cognitive mechanisms, raising the possibility that children’s reading skills could be increased by teaching them how to play an instrument.

In a presentation last week at the meeting of the American Psychological Association, the Northwestern researches, led by Nina Kraus, said the technique worked in two Chicago public schools.

Students with two years of band or choir showed faster neural responses after two years, Kraus reported, than did the control group, students who had taken Junior Reserve Officer Training Classes.

That may be a good reason not to cut funding for music in schools.

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